摘要
光时域反射结构的布里渊散射分布式光纤传感器所检测的自发布里渊散射光信号非常微弱,且频带宽度在几十兆赫以上,难以应用普通相干解调方法.提出了基于希尔伯特变换的光相干检测方法,具体采用微波电光调制产生频移参考光和自发布里渊散射光进行相干检测得到光电信号,再应用基于希尔伯特变换的数字信号处理技术对光电信号进行幅度解调,得到了信噪比改善的布里渊散射光谱,从而有利于提高传感器的检测性能.
The scattering optical signal of BOTDR based on Brillouin scattering distributed sensor is very weak and have a frequency width of several decades megahertz, so it is hard to perform the traditional coherent demodulation. A optical heterodyne detection based on Hilbert transform is presented here. In detail,Brillouin back-scattering light is heterodyne detected with the reference right which is modulated by microwave electric optical modulator to produce frequency-adjustable light, then the detected photoelectric signal is demodulated using Hilbert transform. At last the distributed sensing signal with better S/N ratio is gained, which can enhance the performance of the sensor.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2005年第9期1328-1331,共4页
Acta Photonica Sinica
基金
国家863计划项目(2001AA602022-1)
浙江省自然科学基金(M603127)资助
关键词
光纤传感器
布里渊散射
希尔伯特变换
相干检测
Optical fiber sensor
Brillouin scattering
Hilbert transform
Heterodyne detect
